Semiconductor devices often include multiple layers of conductive, insulating, and semiconductive layers. Often, the desirable properties of such layers improve with the crystallinity of the layer. For example, light propagation is superior in dielectric films of higher crystalline quality. Similarly, the electron mobility and electron lifetime of semiconductive layers improve as the crystallinity of the layer increases. The free electron concentration of conductive layers and the electron charge displacement and electron energy recoverability of insulative or dielectric films also improve as the crystallinity of these layers increases.
Attempts have been made to fabricate high quality crystalline optical waveguide devices. However, such attempts typically have succeeded only on bulk oxide substrates. Attempts to grow such devices on a single crystal semiconductor or compound semiconductors substrates, such as germanium, silicon, and various insulators, have generally been unsuccessful because crystal lattice mismatches between the host crystal of the substrate and the grown crystal of the optical waveguide layer have caused the resulting crystal of the optical waveguide layer to be of low crystalline quality.
Accordingly, a need exists for a semiconductor structure that provides a high quality optical waveguide and for a process for making such a structure. In other words, there is a need for providing the formation of a monocrystalline substrate that is compliant with a high quality monocrystalline optical waveguide material layer so that true two-dimensional growth can be achieved for the formation of quality optical waveguide devices.
Skilled artisans will appreciate that elements in the figures are illustrated for simplicity and clarity and have not necessarily been drawn to scale. For example, the dimensions of some of the elements in the figures may be exaggerated relative to other elements to help to improve understanding of embodiments of the present invention.